First let me start by saying that I don't know if a similar method is posted on BHW however this what I started to do a month ago and it work great. First thing I go on Google and I do a search on a keyword that I know will have a good potential in term of backlink, a great example is "buy cialis". I take a quick look around the results in the first page and I filter the articles, blog posts etc so I can taget the pages that actually sale. Once I have a target I copy the URL, the idea is to get some useful backlink that those pages use. At first I use to past the URL back in Google so I could get all the backlink linking to that page and then I found http://www.iwebtool.com/backlink_checker witch made my work easier. What I do is I copy the URL back in backlink checker, once I get the results I filter the blog posts with good PR, the great thing about this is I get the PR right away and I don't have to worry about NoFollow since they are legit backlink. I found some gold mines using this method, many pr 3,4,5 backlinks in just 15 minutes.